U.S. patent number 9,347,720 [Application Number 13/744,224] was granted by the patent office on 2016-05-24 for ammunition magazine.
This patent grant is currently assigned to MAGPUL INDUSTRIES, CORP.. The grantee listed for this patent is Magpul Industries Corp.. Invention is credited to Richard M. Fitzpatrick, Michael T. Mayberry, Brian L. Nakayama.
United States Patent |
9,347,720 |
Fitzpatrick , et
al. |
May 24, 2016 |
Ammunition magazine
Abstract
A new interface for a magazine follower and floor plate is used
to provide greater stability to the round stack and a more sturdy
system overall. The floor plate is designed with two opposite legs,
the rear being shorter than the front leg so as to facilitate
travel throughout the magazine and clearing of accumulated dirt and
debris. The floor plate, in one embodiment, utilizes a lock plate
that is shaped and sized to become a shoe for the compressed spring
and associated follower. In an alternate embodiment, the floor
plate itself serves the purpose and, with provided teeth, directly
fastens to the magazine casing at notches manufactured in the
magazine wall for that purpose. Other enhancements to the magazine
include at least one matrix of divots to provide a paint surface,
an over-insertion stop and a lower rear geometry to aid in clearing
debris and grit.
Inventors: |
Fitzpatrick; Richard M.
(Longmont, CO), Mayberry; Michael T. (Denver, CO),
Nakayama; Brian L. (Arvada, CO) |
Applicant: |
Name |
City |
State |
Country |
Type |
Magpul Industries Corp. |
Boulder |
CO |
US |
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Assignee: |
MAGPUL INDUSTRIES, CORP.
(Louisville, CO)
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Family
ID: |
48778983 |
Appl.
No.: |
13/744,224 |
Filed: |
January 17, 2013 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20130180146 A1 |
Jul 18, 2013 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61587604 |
Jan 17, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F41A
9/64 (20130101); F41A 9/70 (20130101); F41A
9/65 (20130101); F41A 9/62 (20130101) |
Current International
Class: |
F41A
9/70 (20060101); F41A 9/65 (20060101) |
Field of
Search: |
;42/17,18,6,7,21,22,49.01,50 ;124/45,51.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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200944016 |
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Sep 2007 |
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CN |
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8606162 |
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Apr 1986 |
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DE |
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2805123 |
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Nov 2014 |
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EP |
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2015507733 |
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Mar 2015 |
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JP |
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2013109792 |
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Jul 2013 |
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WO |
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Other References
NPL; Jun. 3, 2011.
http://www.thetruthaboutguns.com/2011/06/foghorn/gear-review-lancer-l5-ad-
vanced-warfighter-magazines/. cited by examiner .
Wikipedia, "Dot Matrix Printing", Webpage found at
https://en.wikipedia.org/wiki/Dot.sub.--matrix.sub.--printing
Inventor(s) aware of prior art on or before Jul. 16, 2015, p. 9.
cited by applicant .
ingunowners.com, "Marking your Magazines?", Webpage found at
http://ingunowners.com/forums/accessories-gear/95433-marking-your-magazin-
es.html Inventor(s) aware of prior art on or before Jul. 16, 2015,
p. 4. cited by applicant .
ingunowners.com, "Pen for Marking Magazines", Webpage found at
http://ingunowners.com/forums/general-firearms-discussion/237593-pen-mark-
ing-magazines.html Inventor(s) aware of prior art on or before Jul.
16, 2015, p. 5. cited by applicant .
Renan Menier, "Partial Search Report of EP 13738364", Oct. 28,
2015, p. 1 Published in: EP. cited by applicant .
"International Search Report and Written Opinion of
PCT/US13/21996", Mar. 28, 2013, p. 8 Published in: WIPO. cited by
applicant .
Cuthbert, Barry, "New Zealand Examination Report", Feb. 23, 2015,
p. 2, Published in: NZ. cited by applicant .
Chenming, Wu, "Chinese Office Action re Application No.
2013800056975", Jul. 12, 2015, p. 18, Published in: CN. cited by
applicant .
Tokai Law Firm, "English Translation of Japanese Office Action
Issued Aug. 19, 2015 for Japanese Application No. 2014-553418",
Aug. 19, 2015, p. 4, Published in: JP. cited by applicant .
Ong, Jennie, "Singapore Office Action re Application No.
11201404050W", Mar. 11, 2015, p. 6, Published in: SP. cited by
applicant .
Poh, Daniel, "Response to Singapore Office Action re Application
No. 11201404050W", Oct. 2, 2015, p. 12, Published in: SP. cited by
applicant.
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Primary Examiner: Abdosh; Samir
Assistant Examiner: Cooper; John D
Attorney, Agent or Firm: Neugeboren O'Dowd PC
Parent Case Text
CROSS-REFERENCES TO RELATED APPLICATIONS
This application claims priority as a perfection of prior filed
U.S. provisional application No. 61/587,604, filed Jan. 17, 2012
and incorporates the same by reference herein in its entirety.
Claims
What is claimed is:
1. An ammunition magazine casing comprising: a. a casing body with
fore and aft sides and two longer lateral sides and first and
second open ends; b. a pair of spines located on an interior of the
aft side of the body, towards the second open end, the spines
defining a trench that extends at least partly toward the first
open end, and the spines stopping at a point in the casing where
the exterior geometry of the casing changes from substantially
curved to substantially straight; and c. a pair of channels, one on
either side of the spines.
Description
FIELD OF THE INVENTION
The present invention relates to the field of firearms and more
particularly relates to an improved ammunition magazine.
BACKGROUND OF THE INVENTION
Ammunition magazines are well known in the art of firearms. Their
basic construction is a containment shell with two open ends. One
end is deemed the "floor" of the magazine and is covered by a plate
while the opposite end is the "feed" end and interfaces with the
weapon. Inside the volume defined by the shell and plate is a
spring and follower assembly. When ammunition is loaded into the
magazine, the ammunition pushes the follower down towards the floor
and thereby compresses the spring. In use, when one cartridge of
ammunition is expended, the compressed spring releases and pushes
the follower and associated ammunition upwards toward the feed end
and the next round of ammunition is thereby readied.
Prior magazines have been manufactured in many different
configurations and of different materials. Perhaps the best known
in the U.S. are the AK-47 and the USGI AR15/M16 magazines. These
magazines function similarly, though they are made with slight
variations to interface with their host system. Of notable
difference is that the AK-47 magazine has a relatively constant
curvature while the AR15/M16 magazine has a less curved lower
region that gradually resolves to a more linear function towards
the feed end. Both use the same type of internal system. Of
particular note with both systems, and all follower magazine
systems, is that the system works well only as the follower
smoothly and levelly travels the inside of the magazine. As the
follower must move, there is room for the follower in all the known
prior art magazines to move axially, or "wobble," and possibly jam.
This is notorious in the AR15/M16 magazine style as the geometry of
the magazine is inherently not uniform. Previous attempts to
address the many issues with the AR15/M16 magazine have been made,
including magazines previously invented by the applicants and
disclosed in U.S. Pat. Nos. 7,908,780, issued Mar. 22, 2011, and
8,069,601, issued Dec. 6, 2011. Both of these patents and products
based upon them have fared well in the market as solutions to
AR15/M16 magazine issues and serve as a basis for the magazine
construction disclosed herein. Accordingly, these two patents are
incorporated by reference in their entirety herein.
Of particular interest in the construction of ammunition magazines
is the shape of and interface between the follower and the
floorplate. The interface needs to be stable when the magazine is
fully loaded and, traditionally, the floorplate has been flat with
the follower having some contact with the floor plate when the
magazine was fully loaded. Various follower designs have been
introduced in efforts to improve the performance of ammunition
magazines; however, there is usually some trade-off between the
motion of the follower and associated round stack and ultimate
stability.
The present invention is a polymer magazine utilizing an improved
floor plate and interfacing follower. The follower is constructed
with fore and aft legs, the fore leg being longer. The floor plate
is generally a two-piece floor plate and lock plate combination,
the lock plate becoming a shoe for the follower when the magazine
is fully loaded. In an alternate, slim-line, version, the lock
plate is omitted and the floor plate serves as the follower's
shoe.
SUMMARY OF THE INVENTION
In view of the foregoing disadvantages inherent in the known types
of ammunition magazines, this invention provides an improved
magazine. As such, the present invention's general purpose is to
provide a new and improved magazine that is backwards compatible
with known weapon platforms and presents a more stable follower and
follower path.
To accomplish these objectives, the improved follower and floor
plate combination provides a lock plate serving as a shoe to
directly and perfectly fit and support the follower when the
magazine is fully loaded. In an alternate embodiment, the floor
plate is so constructed to serve the same purpose without the lock
plate. The follower, in either event, is constructed in a manner to
facilitate travel throughout the length of the magazine body.
The more important features of the invention have thus been
outlined in order that the more detailed description that follows
may be better understood and in order that the present contribution
to the art may better be appreciated. Additional features of the
invention will be described hereinafter and will form the subject
matter of the claims that follow.
Many objects of this invention will appear from the following
description and appended claims, reference being made to the
accompanying drawings forming a part of this specification wherein
like reference characters designate corresponding parts in the
several views.
Before explaining at least one embodiment of the invention in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangements
of the components set forth in the following description or
illustrated in the drawings. The invention is capable of other
embodiments and of being practiced and carried out in various ways.
Also it is to be understood that the phraseology and terminology
employed herein are for the purpose of description and should not
be regarded as limiting.
As such, those skilled in the art will appreciate that the
conception, upon which this disclosure is based, may readily be
utilized as a basis for the designing of other structures, methods
and systems for carrying out the several purposes of the present
invention. It is important, therefore, that the claims be regarded
as including such equivalent constructions insofar as they do not
depart from the spirit and scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a magazine utilizing an embodiment
of the invention.
FIG. 2 bottom plan view of the magazine of FIG. 1.
FIG. 3 is a top plan view of the magazine of FIG. 1, with its
spring compressed.
FIG. 4 is sectional view of the magazine of FIG. 3, taken along
line A-A.
FIG. 5 is a close up view of the magazine of FIG. 4, taken in
circle B.
FIG. 6 is a perspective view of the follower, lock plate and spring
of the magazine of FIG. 1.
FIG. 7 is a side elevation of the follower, spring and lock plate
of FIG. 6.
FIG. 8 is a rear elevation of the follower, spring and lock plate
of FIG. 6.
FIG. 9 is a perspective view of a magazine using an alternate
embodiment of the invention
FIG. 10 is front elevation of the magazine of FIG. 9.
FIG. 11 is a rear elevation of the magazine of FIG. 9.
FIG. 12 is a top plan view of the magazine of FIG. 9, with its
spring compressed.
FIG. 13 is sectional view of the magazine of FIG. 12, taken along
line C-C.
FIG. 14 is a close up view of the magazine of FIG. 13, taken in
circle D.
FIG. 15 is a perspective view of the follower, lock plate and
spring of the magazine of FIG. 9.
FIG. 16 is a side elevation of the follower, spring and lock plate
of FIG. 15.
FIG. 17 is a rear elevation of the follower, spring and lock plate
of FIG. 15.
FIG. 18 is a partial lower perspective view of an alternate
magazine casing.
FIG. 19 is another partial lower perspective view of the magazine
casing of FIG. 18.
FIG. 20 is a sectional view of the casing of FIG. 19.
REFERENCE NUMBERS USED IN THE SPECIFICATION
1--Magazine
2--Magazine Casing
3--Follower Spring
4--Magazine Spine
5--Paint Matrix
6--Front Magazine Notch
7--Magazine Stop
8--Rear Magazine Notch
9--Spine Groove
10--Floor Plate
12--Lock Plate
14--Lock Plate Tab
16--Lock Plate Cradle
18--Lock Plate Pillar
20--Magazine Follower
22--Follower Front Leg
24--Follower Rear Leg
30--Alternate Floor Plate
32--Alternate Cradle
34--Alternate Pillar
36--Cradle Tooth
38--Pillar Tooth
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference now to the drawings, the preferred embodiment of the
ammunition magazine is herein described. It should be noted that
the articles "a", "an" and "the", as used in this specification,
include plural referents unless the content clearly dictates
otherwise.
With reference to FIG. 1, the magazine 1 generally comprises a
generally rectangular casing, having short fore and aft sides and
longer lateral sides and an open floor end and an open feed end.
Feed lips are provided at the feed end to interface with a weapon
and to guide cartridges into the firing chamber of said weapon. The
floor end is capped with a floor plate 10. Ideally, floor plate 10
is secured by a lock plate 12 (FIG. 5). The manner in which the
lock plate 12 secures the floor plate 10 is as follows: the floor
plate 10 is configured to slide over a rim at the floor end of the
magazine. The lock plate 12 rests against the floor plate 10 and is
under pressure from the follower spring 3. A tab 14 of the lock
plate 12 is positioned to pass through an orifice of the floor
plate (FIG. 2). As the lock plate 12 is under pressure, the tab
maintains its position and prevents the floor plate 10 from sliding
off of the magazine's rim.
As shown in FIGS. 4-8, the follower 20 may be constructed with rear
leg 24 shorter than the front leg 22. This construction makes the
system clear dirt and grime easier than having the two legs equal
in length. To compensate for the shortened leg 24, a pillar 18 is
constructed on the lock plate 12 in a manner to abut the shorter
rear leg 24 when the spring 3 is compressed. Together, the pillar
18 and shorter rear leg 24 should be about equal to the length of
the forward leg 22. Together, these structures will prevent the
spring 3 from being over-compressed and provide greater stability
to the round stack and system when the spring is compressed to its
maximum extent.
Another improvement is the addition of a cradle 16 at the fore end
of the lock plate 12. The cradle 16 extends into the magazine body
and will interface with the forward leg 22 as the spring 3 is
compressed. The cradle 16 serves as a block in the instance where a
large amount of force compresses the spring 3 and, in turn, pushes
the lock plate 12 and floor plate 10 slightly beyond the lower rim
of the magazine 1. Without the cradle 22, such circumstances may
cause the lock plate 12 to slip out of alignment with the magazine
casing. The cradle 22 also contributes to follower stability at the
lower magazine extremity. Together, the pillar 24 and cradle 22
make the lock plate 12 a type of shoe for the spring 3 and follower
20.
FIG. 9 depicts a magazine utilizing an alternate embodiment of the
invention where the floor plate 30 is a slim-line floor plate and
performs functions of both the floor plate 10 and lock plate 12 of
the previous embodiment. Modified floor plate 30 engages notches 6
and 8 on the front and back sides of the magazine 1 respectively,
shown in FIGS. 10 and 11. Like the previous embodiment, the
modified floor plate 30 becomes a shoe for the spring 3 and
follower 20, as shown in FIGS. 12-14. Floor plate 30 provides a
pillar 34 for the rear leg 24 of follower 20 and a narrower cradle
32 for the forward leg 22. These structures function generally in
the same manner as described above. Of note, both cradle 32 and
pillar 34 have teeth 36, 38 which interface with notches 6, 8 in
the magazine body, thus securing the floor plate 30 to the magazine
1 (FIGS. 1 5-1 7).
Another improvement to the structure of the magazine is illustrated
in FIGS. 18-20 where a pair of spines 4 is built into a lower hind
area of the magazine. Spines 4 are in essence a continuation of a
trench in the rear of the magazine that nests the rear leg 24, as
can be seen in FIG. 5. The spines 4 are essentially formed by
removing material from the wall of the magazine around the trench,
forming two channels 9 on either side of the spines 4 with the
trench continuing therebetween. Ideally, the spines 4 and channels
9 may extend as far up the magazine as the point where the exterior
geometry straightens so as to be inserted into a magazine well of a
firearm, roughly as far as over-insertion stop 7 in FIG. 9. The
purpose of this construction is to aid in clearance of debris and
grit and to improve processing in general. As the spines 4 are, in
essence, a continuation of the trench, the follower is guided by
them and, if extended far enough up the magazine, the point where
the channels 9 end could be used as an internal follower stop.
In all of these embodiments, the preferred magazine body is
comprised of a glass-reinforced thermoplastic polymer selected to
resist the heat generated from firing a rifle. However, other
polymers, like polycarbonate, may be used and the magazines may be
made in any color or opacity (which can reduce or eliminate the
need for a magazine level indicator). Some polymers, such as
polycarbonate, may be used without reinforcement. Steel, carbon
fiber, and other materials may also be used to reinforce the
magazine. Likewise, the magazine body may be made of other
materials having suitable strength and durability, such as
titanium, ceramics, laminates, amorphous metals, etc. The follower
is preferred to be made of polyoxymethylene, acetal resin available
commercially from DuPont under the trade name DELRIN.RTM., though
other materials are suitable, just not preferred. The magazine body
may also feature improvements to aid the user in other manners
(FIG. 1). At least one paint matrix 5 may be added to either the
body or floor plate 30 of the magazine. Paint matrix 5 is a
plurality of divots in the body of the magazine that, when painted
over with some form of mark or indicia, will hold the paint mark
within the cavities of the divots. An over-insertion stop 7 (FIG.
9) may also be provided so that the magazine will abut the walls of
the magazine well and so prevent over-insertion of the
magazine.
Although the present invention has been described with reference to
preferred embodiments, numerous modifications and variations can be
made and still the result will come within the scope of the
invention. No limitation with respect to the specific embodiments
disclosed herein is intended or should be inferred.
* * * * *
References